Centrifugal bowl with reciprocating valve for separating sludgecontaining liquids



April 19, 1949. T. v. HANNO 2,457,742

' CENTRIFUGAL BOWL WITH RECIPROCATING VALVE FOR SEPARATINGSLUDGE-CONTAINING L IDS fan/613. 25 /M/Wra/f y Aprll 19, 1949. T. HANNO2,467,742

CENTRIFUGAL B WITH RECIPROCATING VALVE Foa SEPARATING sLUDGE-CONTAININGLIQUIDs Flled May 2O 1944 2 Sheets-Sheet 2 5)/ @man Mem 4,7

Patented Apr. 19, 1949 CENTRIFUGAL BOWL WITH RECIPROCAT- ING VALVE FORSEPARATING SLUDGE- -CONTAINING LIQUIDS Tore Verner Hanno, StoraEssingen, Sweden, as-

signor to The De Laval Separator Company, New York, N. Y., a corporationof New Jersey Application May 20, 1944, Serial No. 536,462 In SwedenJuly 13, 1943 Claims.

' ing problems of this kind it is therefore preferred to use centrifugalbowls provided either with small nozzles in the wall of the bowl anddesigned for continuous discharge of the'sludge, or with devices forintermittent discharge of the sludge during operation. In the lattercase a construction of centrifugal bowl is generally used which permitsthe upper or the lower part to be moved axially relative to the otherparts of the bowl, a slot thereby being formed thru which the contentsof the bowl escape. Such a construction, however, has the conveniencethat a dry sludge cannot be discharged, because the liquid contained inthe bowl i'lows out together with the sludge, and this entails thefurther inconvenlence that the supply of liquid to the bowl must be shutoil? each timethe bowl is to be emptied. l

With a view to avoiding these inconveniences a plurality of deviceslcomprising openings or channels in the bowl wall have been suggested. Inthese constructions the openings are covered either by an axiallymovable slide or by valves, suscptibleof being opened during operation.The inconveniences with the known devices comprising a slide are thedifficulty to obtain large packing rings of suicient durability andcapable of making a tight joint, and above all to get the openingintervals sufciently short, so that only part of the sludge contained inthe bowl is discharged each time. The valves .heretofore suggested arecomplicated and sensitive and often untight, because sludge particleseasily penetrate between the cone and the seat of the valve. The objectof the invention is an arrangement in centrifugal bowls, the wall ofwhich is provided with channels or openings for the discharge of thesludge separated in the bowl, which channels or openings are covered byone or more movable members. for instance slides or the like, providedwith openings which, when the movable members occupy agiven position,communicate with corresponding openings in the bowl wall, and ischaracterized in that each outlet opening in the bowl wall is providedwith a tightening device, e. g. in the form of an elastic pack- 2 ing,collar, etc., making a tight joint both with the bowl wall and theslide. In a preferred construction the packing is thereby fixed to thebowl wall by means o f an annular nut or the like. The pressureestablishing the tightjoint with the slide is generated both by thecentrifugal force and the liquid pressure. In order to enable quickopening and closing each outlet opening should advantageously beprovided with a small slide.

Figure 1 of the accompanying drawing shows one embodiment of theinvention in longitudinal section. Figure 2 is a cross section on theline 2-2 of Figure 1. Figures 3, 4 and 5 are views in longitudinalsection of other embodiments of the invention. k

In all figures the following denominations are used: I is the lower partor shell of the centrifl' ugal bowl, carried by a bowl spindle 2. 3 isthe upper part or top of the bowl, and 4 its annular outlet forseparated liquid; 5 a coupling ring by which the bowl top 3 and the bowlshell I are held together. unseparated liquid, and l is the supply pipefor the liquid. 38 is a pile of conical discs. On its largest innerdiameter the bowl shell I is provided with a number of round openings 8,each of which opens into a cylindrical chamber 9, positioned at rightangles to the openings and communicating with the outside of the bowlthru the oblong opening I0. The cylindrical chamber 9 is provided withan exchangeable lining II and its upper end is covered by a screw-plugI2; in the chamber 9 there is a cylindrical slide I3, provided on themiddle with a plane surface I4. An opening I5 is provided at rightangles to the surface I4. f

In each of the openings 8, which are provided with a threaded part I6,is arranged a sleeveor cup-shaped packing I1 having a central opening I8and a flange I9, the latter being squeezed fast to the bowl shell I bythe annular nut 20 andthe outerv part of which contacts with the planesurface I4 on the slide I3. The length of the slide I3 is less than thatof lthe cylindrical chamber 9.

On the lower side of the centrifugal bowl two receiving chambers 2l' and22 are arranged into which a Iservo liquid can be fed vthru thestationary tubes 23 and 24. 'The chamber 2| communicates with thelowermost part of the cham- 6 is a receiver and distributor of ber 9 bya channel 25 and the chamber 22 with the uppermost part of the samechamber thru a channel 26.

In the embodiment according to Fig. 1, the bowl shell I is provided witha drain channel 21 running from the upper part of the chamber 9 to theoutside of the bowl and located at a distance from the lower side of thescrew plug I2 approximately equal to the difference between the lengthof the chamber 9 and that of the slide I3, that is the length of strokeof the slide. Another channel 28 is provided at the same distance fromthe bottom of the chamber 9. The opening I in the slide is so located asto communicate with the opening I8 in the packing I1 when the slideoccupies its highest position.

The bow] operates in the following manner.

Servo liquid is fed thru tube 24 into the chamber 22 whence it passesthru the channel 26 to the upper end of the slide which is therebyforced down to its lower position, so that the communication between theopenings I5 of the slide and the opening I8 of the packing isinterrupted. The supply of servo liquid is now shut off, and the liquidcontained in the chamber 22, the channel 26,-

and the upper part of the chamber 9 escapes thru the opening 21, sincethis is not covered. When a suitable amount of sludge has accumulated inthe sludge space of the bowl, servo liquid is introduced into thechamber 2i and is conducted thru the channel 25 to the lower end of theslide, which is then forced up until the openings I5 and I8 communicate,whereupon the supply of servo liquid is shut off. When a suitable amountof sludge has been thrown out, the opening in the bowl is closed againby feeding liquid into the chamber 22. It is thus necessary to use servoliquid only at the opening and closing intervals, and consequently theconsumption of such liquid is very small.

If the opening interval must be very short in order to prevent liquidfrom escaping with the sludge, the construction of slide shown in Fig. 3may be used. The opening I5 of the slide is placed in such a manner thatthe communication between the openings I5 and I8 is interrupted both inthe uppermost and the lowermost position of the slide, that is theopenings communicate with each other only when the opening I5 is passingthe opening I8. By regulating the supply of servo liquid it is possibleto change the speed of the slide and thus to shorten the openinginterval down to a fraction of a second. In that case only one of thetubes 23 and 24 need be used for a complete emptying operation.

In order to make a satisfactory tight joint the packing I1 should bemade of an elastic and comparatively soft material, but this entailsrapid wear of the packing in case hard sludge particles penetratebetween the packing and the slide. With a view to preventing this, thepacking I1 in Fig. 3 is provided with a sleeve 29 of metal, Bakelite, oranother hard and resistive material. The sleeve should have sharp edges,especially on its inside, on the part contacting with the slide, becausesludge particles are then prevented from getting between the slide andthe packing, In order to avoid deformation of the cylindrical part ofthe packing sleeve by the high interior pressure, a reinforcing sleeveof metal. or the like may be arranged around this part, or the opening 8may be so dirnensioned, as shown in Fig. 3, that there is only a smallplay between the packing sleeve and the wall of the bowl shell.

Although only two embodiments are illustrated,

it will be understood that a great many modifications are possiblewithin the scope of the invention. The packing sleeve I1 need not haveany special shape or be of any special material. It may, for instance,be in the form of metal bellows 30 (see Fig. 4) to which packingmaterial is vulcanized. Instead of supplying servo liquid at both endsof the slide, a spring 3| (see Fig. 5) may be arranged at its one end bywhich the slide is forced back into its initial position. In this case adrainage must however also be provided, for instance in the form of asmall opening 32 thru which the servo liquid escapes from the chamber 9.

What I claim and desire to protect by Letters Patent is:

1. In a centrifugal bowl the wall of which encloses a number of chambersextending parallel to the axis of the bowl, the bowl wall havingdischarge openings one between each chamber and the outside of the bowl,the bowl wall having inner openings one between each chamber and theinside of the bowl, sliding members, one in. each chamber, each having alongitudinally extending plane inside surface and a through orificeadapted, in one position of the sliding member, to connect the twoopenings, means, including a channel through which a servo liquid isadapted to flow, whereby the movement of each sliding member iscontrolled, and in each inner opening a packing device having an openingcommunicating with the corresponding inner bowl wall opening and makinga tight joint both with the bowl wall and with the plane surface of thesliding member.

2. A centrifugal bowl comprising a wall having an outlet openingcommunicating with the interior of the bowl, a packing device mounted inthe opening and defining a passage for the discharge of solid particlesand sludge separated in the bowl, the packing device making a tightjoint with said wall to seal the opening except for said passage, areciprocable member slidable in the bowl wall and having a surfacemaintaining a tight joint with the packing device around said passage inthe movement of the member, said member being operable in its movementto alternately open and close said passage, and means for controllingthe movement of the sliding member.

3. A centrifugal bowl as defined in claim 2 in which the packing deviceincludes a flexible element having a wear-resistant sleeve defining saidpassage and contacting said surface of the slidable member.

4. In a centrifugal bowl the wall of which is provided with a pluralityof separate openings communicating with the interior of the bowl for thedischarge of solid particles and Ysludge separated in the bowl, slidingmembers, one covering each opening, each sliding member being providedwith an outlet, means, including a channel in which a servo liquid isadapted to flow, by which the movement of said member is controlled, anda packing device in said opening; said packing device comprising anelastic cup-shaped member having a part contacting the sliding memberand having an opening in said contacting part communicating with thecorresponding inner bowl opening and having, around the other end, anexterior flange, and an annular nut securing the said flange to the bowlwall, thereby making a tight joint with the bowl wall and with the planesurface of the sliding member.

5. In a centrifugal bowl the wall of which is zum 5 provided with aplurality of separate openings communicating with the interior of thebowl for the discharge of solid particles and sludge separated in thebowl, sliding members, one covering each opening, each sliding memberbeing provided with an outlet, means, including a,f channel in which aservo liquid is adapted to flow, by which the movement of said member iscontrolled, and

Va packing device in said opening; said packing device comprising acup-shaped flexible member having a part contacting the sliding memberand having itself an opening in said contacting part communicating withthe corresponding opening communicating with the interior of the bowl,and a, wear-resistant sleeve surrounding the opening adjacent thesliding member and in contact therewith.

TORE VERNER HANNO;

REFERENCES CITED Thefollowing references are of record in the tile ofthis patent:

5 UNITED STATES PATENTS Number Name Date 1,635,482 Joyce July 12, 19271,921,181 Fawcett Aug. 8, 1933 lo 2,022,815 Strezynski Dec. 3, 19352,087,727 Bath July 20, 1937 2,091,329 Nyrop Aug. 31, 1937 2,126,864Bath Aug. 16, 1938 FOREIGN PATENTS l5 Number Country Date 22,085 GermanyJune 27, 1883 e 451,251 Great Britainl July 31, 1936

